Topping up your coffee cup throughout the day could provide some protection against common cancers affecting the mouth, throat, and voice box, according to a new study.

Researchers in the US gathered more than 25,000 records collated in 14 previous studies, evaluating them collectively to determine what stands out in the diets of individuals with various tumors of the head and neck.

Their results suggest more than four cups of caffeinated coffee each day could decrease your odds of developing cancer of the head or neck by as much as 17 percent.

For those who don’t like the caffeine buzz, or who prefer to start the day with a spot of English Breakfast or Earl Grey, there’s also some good news in the analysis by the International Head and Neck Cancer Epidemiology Consortium.

It’s been shown that what goes into our mouths can trigger tumor-causing mutations on the way to our stomach and lungs. Those who use tobacco products are at 10 times greater risk of developing a head and neck squamous cell carcinoma (HNSCC), with risks also increasing depending on the amount of alcohol consumed each day.

On the other hand, popular beverages such as tea and coffee contain powerful anticancer and anti-inflammatory substances that may potentially shield drinkers from some of the effects of carcinogens.

Research on the topic has been patchy, with some studies hinting that intermediate to high levels of coffee consumption each day might have some protective effects, contrasting with others that failed to see much of an impact on preventing cancers in the mouth and throat area. Similarly, tea also has been associated with a reduced risk of head and neck cancers in some studies, but not in others.

By using an updated set of cases and controls and pooling a larger number of records to include more than 9,500 cases of head and neck cancer and nearly 16,000 controls, the researchers aimed to confirm the precise relationship between coffee and tea consumption and cancers of the tissues they come into contact with.

On a more specific level, those who drank four cups or more of caffeinated coffee had a 30 percent lower risk of developing cancer inside their mouth, and 22 percent lower risk of cancer inside their throat. Having around 3 to 4 cups a day reduced chances of cancer in the lower reaches of the throat by around 40 percent.

Coffee doesn’t even need to be caffeinated to get some kind of benefit. Drinking decaf was associated with a 25 percent drop in cancer of the oral cavity. Tea was linked with a nearly 30 percent decline in cancer of the lower throat, though going in for a second or third cup of tea may flip the odds to a 38 percent greater chance of laryngeal cancer.

Just why this reversal occurs isn’t clear, though past research has found the temperature of your brew might play a role in triggering cancerous changes, implying the relationship between popular hot beverages and our health is complicated by factors beyond chemical makeup.

Head and neck cancers are on the decline in many of the world’s wealthier nations as vaccines against human papillomavirus shield large sections of the population against one of the disease’s most common triggers.

Yet in countries without easy and affordable access to healthcare, head and neck cancers represent a growing burden of illness that warrants effective public health actions to keep it in check.

Nearly 900,000 cases are diagnosed each year, with an annual mortality of close to half that figure. Many who do survive risk debilitating deformities that deprive them of the ability to communicate or to chew and swallow food.

“While there has been prior research on coffee and tea consumption and reduced risk of cancer, this study highlighted their varying effects with different sub-sites of head and neck cancer, including the observation that even decaffeinated coffee had some positive impact,” says University of Utah epidemiologist Yuan-Chin Amy Lee.

“Coffee and tea habits are fairly complex, and these findings support the need for more data and further studies around the impact that coffee and tea can have on reducing cancer risk.”

This research was published in Cancer.